Are large mIPSCs dependent on the Ca2+ released from the internal stores in tectal neurons of Xenopus
- VernacularTitle:爪蟾顶盖神经元的大微抑制性突触后电流(mIPSCs)依赖从钙储池释放的钙?
- Author:
Wang HONG
1
;
Tsai HAO-JAN
Author Information
1. 北京大学
- Keywords:
miniature inhibitory postsynaptic potential (mIPSCs);
voltage-clamp;
calcium ions;
neurotransmitter;
Xenopus;
tectal neuron;
internal Ca2 + store
- From:
Neuroscience Bulletin
2005;21(2):101-110
- CountryChina
- Language:Chinese
-
Abstract:
Objective The goal of this study is to investigate some properties of large and/or small mIPSCs with the treatments affecting pathways of external Ca2+ entry from bath solution or release from the internal stores. Methods Experiments were carried out from layer Ⅵ of slice preparation of the adult Xenopuss optic tectum in vitro using the blind tion with or without EGTA (200 μmol/L), more large mIPSCs were recorded than in control. 4 mmol/L Ca2+ -containing solution for perfusion did not significantly change the proportion of large mIPSCs but gradually increased the mean frequency of small mIPSCs. When bath application of 100 μmol/L Cd2+ , the mean frequency of small mIPSCs was only slightly by bath application of 100 μmol/L carbachol in normal saline perfusion but also in Ca2+ -free bath solution. The frequency of small mIPSCs increased dramatically to 315.63% of control by bath application of carbachol ( 100 μmol/L) in normal saline. However, when the carbachol was added into the Ca2+ -free perfusion solution, the enhancement of small mIPSC odine (30-50 μmol/L) also decreased the frequency of small mIPSCs. Conclusion The frequency of small mIPSCs is mainly dependent on the Ca2+ concentration in bath solution, and the IP3 receptor-mediated SOC and/or CICR mechanisms might be involved in the occurrence and/or the increase of the large mIPSCs.
